1. Field of the Invention
The present embodiments relates to methods, systems, and programs for improving the performance when replicating data from a storage device to another storage device.
2. Description of the Related Art
Network storage, also referred to as network storage systems or storage systems, is computer data storage connected to a computer network providing data access to heterogeneous clients. Typically, network storage systems process a large amount of Input/Output (IO) requests, and to process these IO requests efficiently, the network storage systems must have high availability, speed, and reliability.
Sometimes data is copied from one system to another, such as when an organization upgrades to a new data storage device, when backing up data to a different location, or when backing up data for the purpose of disaster recovery. The data needs to be migrated or replicated to the new device from the old device.
Typically, replication has been a background job because most system administrators have been replicating volumes about once a day. Therefore, replication has not been a performance-critical operation. However, many data storage administrators are increasing dramatically the number of replications performed on data, sometimes replicating thousands of volumes a day multiple times. This means that the replication has to be efficient or the performance of the storage array for processing IOs will degrade.
Further, the problem of efficient replication is sometimes compounded when a volume has a large number of randomly written data, because replicating random data requires more computing resources. For example, as a volume grows, the volume metadata related to stored blocks grows, and finding which blocks to replicate becomes increasingly more expensive as a result of the volume metadata growth.
What is needed is a network storage device, software, and systems that efficiently replicate large amounts of data between systems without impacting the normal operation of the storage device.
It is in this context that embodiments arise.